The speaker feels abandoned and heartbroken after someone has left without explanation. They compare themselves to an old empty house, and that image sets the tone: lonely, neglected, and echoing. The wind banging on the "window to my heart" suggests grief that keeps knocking at them, wearing down their calm until their heart slowly breaks. The line about pain becoming "a normal feeling" is especially sad, because it shows how long the hurt has lasted.
The speaker wants to go looking for the person who left, but stops, realizing the other person's "loud silence" already says everything. Saying nothing becomes its own kind of answer. So the speaker chooses to let them go, offering "freedom and warmth" even though it hurts. The ending, sitting alone in the pouring rain, brings the mood together: sad, quiet, and resigned. There is love here, but also acceptance, and the speaker seems to give up more than they get back.